In contrast with off-car balancing (which removes a wheel from the vehicle) on-car balancing leaves the wheel on the vehicle and a special machine is used to balance the tire, wheel and brake assembly making adjustment for all of these components. Obviously this is the best (and most costly) procedure in obtaining balance.
ON-CAR BALANCE
Meaning of ON-CAR BALANCE in English
English dictionary of automotive terms. Английский словарь автомобильных терминов. 2012